ABSTRACT
Magnetism and electricity are closely related. One can be generated from the other and both have many applications. This chapter discusses magnetism and its applications, as well as how to calculate and measure the strength of magnetic fields. Materials are magnetic because of the way the electrons in materials interact with one another. Atoms have nuclei made of protons and neutrons and "orbiting" the nuclei are electrons. Materials that can be magnetized and retain their magnetism are called permanent magnets. A solenoid actuator is a solenoid with a movable cylinder that can be extended or retracted with a magnetic field when the coil is energized. The solenoid actuator can be used to open/close valves, door locks, and many other devices that require a linear actuation. A magnetically levitated train consists of superconducting magnets placed on the bottom of the train and normal coils placed in the track.
